package NC13_二叉树的最大深度;

class TreeNode{
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;
}

public class Solution {
    /**
     *
     * @param root TreeNode类
     * @return int整型
     */
    public int maxDepth (TreeNode root) {
        // write code here
        if (root == null){
            return 0;
        }
        return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));
    }


}